Which of the following might contain a serious threat to the external validity of a study?
a. a survey with a return rate of 30%
b. statistically significant findings in both the clinical setting and at home
c. evidence of a consistent effect in the winter and the spring
d. evidence that shows SAT scores and GPA change with improved study habits
A
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Voluntary nonvoting is synonymous with being denied the legal right to vote
Indicate whether the statement is true or false.
People and nations will start to practice ________ if they come to believe that they are in an economic war
a. protectionism b. free trade c. mercantilism d. neo-mercantilism e. liberalism
Southern miscegenation laws that banned interracial marriage or cohabitation are an example of
A. the separate but equal doctrine. B. a grandfather clause. C. de facto segregation. D. de jure segregation. E. the Black Codes.
One unintended result of the immigration legislation signed by President Johnson in 1965 was "chain migration," under which
A) ?more persons than anticipated from Africa and Asia with specified technical skills or education applied to immigrate. B) ?some immigrants would reapply for residence repeatedly, making it hard to send them back to their home countries when their visas expired. C) ?people from certain regions of foreign countries uncovered loopholes in the law allowing many more people than expected from certain villages, for example, to immigrate. D) ?people repeatedly applied for immigration from different countries until they were successful, using fraudulent documentation that the U.S. immigration system was ill-prepared to evaluate. E) ?immigrants would petition for their relatives to come to the United States.